The immunochemical properties of gastrointestinal mucin type glycoproteins will be examined to determine the potential of these glycoproteins as organ specific markers and to be determine the extent of their immunologic relatedness. Mucins will be isolated from the various anatomic regions of the gastrointestinal tract as well as ovarian cystadenocarcinoma fluids. The mucins will be characterized as to amino acid and carbohydrate composition. Antisera will be prepared with each individual mucin preparation, and the specific antibody purified by absorption and affinity procedures. the organ distribution (specificity) will be examined by immunohistochemical procedures employing normal adult tissues as substrates. A sensitive radio immunoassay will be developed and employed for heterologous inhibition studies in order to examine immunochemical relatedness between individual mucin preparations. The potential role of the antigens as tissue markers will be analyzed by a retrospective study of biopsy specimens from individuals with begin and malignant disorders of both gastrointestinal and extragastrointestinal tissues.